1. Field of the Invention
The present general inventive concept relates to an image forming apparatus and an auto color registration method thereof, and more particularly, to an image forming apparatus having an improved auto color registration function and an auto color registration method thereof.
2. Description of the Related Art
An image forming apparatus generally includes a printer, a scanner, a multifunction device, etc. to form a color image.
The image forming apparatus includes a laser scanning unit (LSU) which is provided corresponding to a plurality of colors, and an image forming unit which includes a plurality of photosensitive bodies, etc. Here, the plurality of photosensitive bodies is arranged along a moving path of a printing medium which is transferred by a transfer unit such as a transfer belt.
For precise printing of a color image, positions where image transfer to the printing medium starts should correspond with each other for the plurality of colors, and likewise, positions where the image transfer to the printing medium ends should correspond with each other for the plurality of colors. To this end, the image forming apparatus performs an auto color registration (ACR) function. The ACR is performed to inspect whether or not the images of the plurality of colors are correctly registered and to automatically correct possible mis-registration.
Particularly, the image forming apparatus detects positions of a plurality of detection marks formed on the transfer belt corresponding to the plurality of colors, and performs the ACR for all the plurality of colors if any color is shifted out of position.
Typically, several sets of the plurality of detection marks are necessary for the ACR to determine whether or not the position correction should be performed, and thus, a lot of developers are needed.
Further, even if detection marks corresponding to any one color are shifted out of position, the ACR should be performed of all the colors, thereby increasing consumption of the developer.
Furthermore, the developer consumption increase causes increase in costs for new developer purchase and waste developer disposal, and various problems like developer scattering, and life shortening of the apparatus and environmental contamination.